The objective of the proposed research is to use nuclear magnetic resonance spectroscopy, Neutron diffraction and Raman scattering techniques to obtain information about the structure and function of a variety of respiratory proteins and respiratory protein-lipid complexes in solution, in membranes, and in the crystalline solid state. Fourier transform NMR spectrometers will be used to study the 31P, 2H and 13C NMR of these systems, to answer the following questions: What is the nature of the protein-lipid interaction between cytochrome c oxidase, cytochrome b5 and lipid? What are the differences between the structures of the respiratory proteins myoglobin, cytochrome c and hemoglobin in solution and in the solid state? First, we will use NMR of specifically 2H-labelled lipids to investigate the nature of protein-lipid interactions between cytochrome oxidase and lipid (phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and cardiolipin) using 2H quadrupole splittings and 31P chemical shielding anisotropies to try to elucidate the dynamic structure of these lipid-protein complexes. In addition, we will obtain additional structural information on these complexes by using neutron diffraction 1H-2H difference Fourier techniques, Raman spectroscopy of the 2H-labelled species, scanning calorimetry and freeze fracture electron microscopy, and will explore the possible structural uses of "magic-angle" carbon-13 NMR chemical shifts. Second, we will investigate the structures of proteins in solution and in the crystalline solid state by means of high-resolution 13C NMR in sideways-spinning and "magic-angle" sample spinning probes. We will attempt to solve the problem of the origin of the 13C chemical shift nonequivalences seen in native proteins in solution, by comparing crystalline protein 13C chemical shifts with a variety of parameters obtained from x-ray coordinates. In this way we hope to make 13C chemical shifts of proteins in solution useful in structural analysis. In addition, we will build a cryogenic probe and preamplifier using a superconducting quantum interference detection system (SQUID) for increasing signal to noise ratios in 13C and 2H NMR.